This document provides a quick review of key concepts from the AP Environmental Science Unit 1 on the living world. It summarizes ecosystems and biotic factors like predator-prey relationships. It also outlines different biomes and aquatic biomes. Additionally, it reviews several nutrient cycles like carbon, nitrogen, phosphorus and hydrologic cycles. It defines primary productivity and trophic levels, and notes energy is lost at each trophic transfer.

1. AP EnvironmentalScience
Quick Review
Unit 1: The Living World
Hosted byBy: Name

2. ● Intros
● 1.1 Introduction to Ecosystems
● 1.2 Terrestrial Biomes
● 1.3 Aquatic Biomes
● 1.4 The Carbon Cycle
● 1.5 The Nitrogen Cycle
● 1.6 The Phosphorus Cycle
● 1.7 The Hydrologic (Water) Cycle
● 1.8 Primary Productivity
● 1.9 Trophic Levels
● 1.10 Energy Flow and the 10%

3. Introduction to Ecosystems
Available resources (water, nutrients, light and space) in any given area
will dictate how plants and animals complete.

4. ● Predator- Consuming another organism
● Prey - Eaten by a predator
● Symbiosis- Long term interaction between two species
○ Mutualism: 😀-😀
○ Commensalism: 😀-😐
○ Parasitism: 😀-😟
● Competition - for space, food, water or mate.
● Resource partitioning - organisms find ways to share!
○ Moth/butterfly.

5. Terrestrial Biomes
Ares on Earth have different biomes or environments due to their
location and the amount of water, temperature and sunlight they have.

6. ● Climate - Long term temperature and precipitation.
● Biome - The given climate of an area and the plants and animals that
have adapted to live there.
● Biomes Type - taiga, temperate rainforests, temperate seasonal
forests, tropical rainforests, shrubland, temperate grassland, savanna,
desert, and tundra.
● Distribution of these biomes depends on wind patterns bringing
precipitation and solar radiation levels.

7. Aquatic Biomes
Aquatic biomes are characterized by the conditions and location of water.

8. ● Fresh water - without salt.
○ Streams, rivers, ponds and lakes.
● Marine - with salt
○ Oceans, Coral reefs, marshlands and estuaries.
● Ocean environments change based on the depth,
temperature, available nutrients.
○ Different marine biomes provide varying degrees of
resources to humans.

9. The Carbon Cycle
Carbon makes up all living things and is constantly cycling via
combustion/metabolism and photosynthesis.

10. ● Carbon is stored in organisms beginning with the process of
photosynthesis.
● Carbon is released into air via combustion or metabolism
(cellular respiration).
● Carbon can be stored for millions of years in ‘sinks’ as dead
organisms are buried in the Earth.
○ These sinks become fossil fuels like oil, methane and coal.
○ When fossil fuels are burned the carbon is released back
into the air.

11. The Nitrogen Cycle
Nitrogen is a necessary nutrient for plant growth and is primarily found
as a gas in the atmosphere.

12. ● Nitrogen fixation-
When bacteria in the
soil convert ammonia
into a form that is
suitable for plants to
use.
● Fertilizer- Humans can
artificially introduce
excess nitrogen.

13. The Phosphorus Cycle
Phosphorus is often the limiting factor of growth in many ecosystems
and stored mostly in rocks.

14. ● Limiting factor for plant growth
● Fertilizer - Humans can artificially introduce it
● Eutrophication - excessive plant growth in natural aquatic
ecosystems.

15. The Hydrologic (Water) Cycle
Water move around Earth in solid, liquid and gas forms.

16. ● Powered by the sun
● Very little fresh water by comparison 2.5%
● VERY VERY little available fresh water

17. Primary Productivity
Primary productivity is when plants convert solar energy into organic
materials.

18. ● Gross primary productivity - total rate of photosynthesis
● Net primary productivity- amount stored
● Very high in the top 100m of the ocean.

19. Trophic Levels
Energy flows from one organism to the next as they are consumed.

20. ● Energy moves up at a
rate of 10% each level.
○ 90% lost as heat.
● Matter flows in cycles.
● This rule can be applied
to human food
consumption and
conservation.